Cripple Wall Bracing: Foundation Repair For Foundation Problems
Cripple Wall Bracing
A cripple wall is a short stud wall that extends from the top of the perimeter foundation upward to support the floor joists. The potential danger comes from the fact that though cripple walls are designed to bear weight from above, the lateral load caused by an earthquake can cause them to hinge over and collapse like dominoes. One of the common foundation problems is that cripple walls in older homes may have been weakened by dry rot or moisture from leaky pipes and could collapse even under the weight of the structure alone. Cripple wall bracing is one of the key components of foundation repair that can prevent the potentially disastrous and economically devastating effects of an earthquake.
Foundation Repair
Not all homes have cripple walls, but that won’t stop opportunistic contractors from offering to brace them. Cripple wall bracing is done by installing plywood sheets called shear walls which span the studs and help resist lateral stress. Shear walls should cover at least 50 percent of the entire cripple wall area for one story structures with increasing percentages for two and three story structures. Vent holes should be provided for ventilation and inspection of foundation repair bolts, and should be covered with a protective screen to prevent infestation. Braces should also be installed around the entire rim joist perimeter, connecting the cripple wall to the floor to prevent shifting.
